This invention relates to an improvement of an apparatus for conically machining the end face of an optical fiber connector.
Optical fiber connectors are used for optically connecting optical fibers in the field of optical communications or optical sensors. In connecting the optical fibers, the end face of each optical fiber is generally machined into a spherical surface in order to minimize the optical coupling loss.
In the machining operation, first the flat end face of the optical fiber is machined into a conical surface, and then the conical surface is ground into a spherical surface.
For instance, Japanese Patent Application (OPI) No. 34763/1987 (the term "OPI" as used herein means an "unexamined published application") has disclose a machining method in which, a concave grinding disc is rotated while the center of the radius of curvature of the ferrule provided for an optical fiber is swung. The machining method, being fundamentally based on the lens polishing method, employs a compound rotation mechanism and swing mechanism at the abrasives supporting section.
However, the conventional machining method is disadvantageous in the following points: The method needs the special concave grinding disc whose concave surface is difficult to form with high accuracy; that is, the concave grinding disc used is not sufficiently high in manufacturing accuracy. In addition, since special motions are employed in combination in the machining method, the mechanisms for realizing the motions are troublesome to adjust. Thus, the conventional machining method is not practical at the work site.
Japanese Patent Application Publication No. 42753/1987 has proposed a machining method in which the ferrule is rotated in a reciprocation mode while being held at a predetermined angle. However, the method has not been put in practical use yet, because it is difficult to set the angle of inclination, and the apparatus for practicing the method is intricate in construction.
Some of the present inventors have proposed a method in which a conical machining operation is carried out by using a cylindrical grinding wheel and a profiling tapered member. However, an apparatus for practicing the method has not been proposed yet.